The purpose of this program is to establish a liver transplantation data base in order to collect data from patients and donors in the United States who have been evaluated and have had liver transplantation for a variety of end stage liver diseases. After being collected, data relating to a patient's condition prior to the operation, during the operation and in the early and late post-operative periods will be evaluated. Collection and evaluation of data on the donor liver also will be done. The collected and evaluated data will be made available to investigators and clinicians.